Thailand's football chief wants a third consecutive AFF Suzuki Cup title but has warned that the improving Malaysia, Singapore and Philippines squads make the 2018 edition that much harder.

After winning the 2014 and 2016 titles, the War Elephants kicked off their defence in Bangkok last week with a 7-0 win over Timor Leste but are aware that the challenge from rivals is increasing.

"We always want to win and we will always do our best but we know that standards in the region are improving," Somyot Poompanmoung, the president of the Football Association of Thailand, told ESPN.

"We can see that Malaysia and Singapore are developing and these countries have a lot of history in the region. The Philippines have improved and they have also hired a famous coach in Sven-Goran Eriksson. All of these teams have ambition.

"They are all our rivals and we are honoured that they are our rivals."

Somyot, elected in 2016, also believes Vietnam are a threat.

"They will also be tough opponents but if we want to win the title again then we have to be at our best," he said.

Thailand are without four of their stars from the 2016 triumph. Chanathip Songkrasin, Teerasil Dangda -- respective tournament MVP and top scorer from two years ago -- and Theerathon Bunmathan are all playing in Japan. Also unavailable is star goalkeeper Kawin Thamsatchanan as he is busy with his Belgium club OH Leuven.

Somyot Poompanmoung says that a third AFF Cup title in a row will be difficult for the War Elephants.

"We are missing some players but if we prepare our team enough, then we can win but football is football and anything can happen," added Somyot. "All teams have a chance this time and it should be a great competition."

Thailand continue their Group B campaign against Indonesia on Saturday and then take on the Philippines and Singapore. The top two teams from both groups progress to the last four.

As well as this regional competition, Thailand are also looking forward to the 2019 Asian Cup and a group with hosts the United Arab Emirates as well as Bahrain and India.

"The Asian Cup is a big tournament for us," Somyot said. "We want to get to the second round there but for now we are focusing on the Suzuki Cup."